Reinforcing-bar for concrete and similar structures.



W. G. GORYELL. REINFORGING BAR FOR comcamr: AND SIMILAR smuewnss.

APPLIOATION FILED IA! 32, 1908 Patented 00$. 21

R 10. F1 12. Part4. Fnqale FIG. l7.

INVENTOR MMW L7 WITNESSES 1 291666077 LS'LQ WILLIAM C. CORYELL, OF YOUNGSTOWN. OHIO.

REINFORCING-BAR FOB CONCRETE AND SIMILAR STRUCTURES Specification of Letters Patent.

Patented Oct. 21, 1913.

Application filed May 22, 1998. Serial No. 484,371.

To all whom it may concern.

Be. it known that I, VILLIAM C. CouYrLL,

a citizen of the United States, residing at -ciently perform its functions in the corn structious in which it is employed. .To this end, I have provided a bar having a central body and one or more of obliquely ar ranged transverse ribs. The body of the bar confori'ns generally to some. regular standard shape, and the ribs are short, preferably extending not more than half Way around the body of the bar, and in themselves vary in cross-sectional area from a maximum near their-centers to a. minimum at their ends. The bar is of approxin'iately uniform cross-sectional area throughout, the area of the body bearing a constant ratio to the aggrcgatearea of the ribs, and the parts of the bar are preferably arranged so as to prevent. its twisting under the forces to Which it is subjected when in service. This may be accomplished by giving all the ribs the same direction of obliquity, forming the body of the bar with a non-circular cross section and then twisting the bar a Whole in a direction opposite to that. of the obliquity of the, ribs; or it may be done by pairing each rib with another having an opposite angleof obliquity. Obviously, in qiiractieing my invention, the section of the body of the bar may he variously formed,

and the ribs may be distributed over the body according to many diflereut arrangements and such distribution may be combined. with a twist in the bar or not, expedien v or design may dict-ate.

The character of the invention, and the manner in which its several possible embodiments meet the requirements of economical production at the rolling mill and of ellicient service in reinforced. structures, will'be best understood upon consideration of the following detailed description, taken in connection with the accompanying drawleg, and the scope of the invention will be particularly pointed out in the appended claims.

In said drawing, Figures 1-6; Figs. 7-47; Fig. 18; Fig. 19, and Figs. 20-22, respectively, illustrate five different embodiments of my invention. Fig. 1 is a perspective view of a bar having two sets of ribs; Figs. 2 and 3 are side and bottom views, respectively, of the same; Fig. 4 is a development of its surface, and Figs. 5 and 6 are sections taken on planes indicated by line 5-5 of Fig. and line. 66 of Fig. 3, respectively. F ig. 7 is acperspectivcview of practically the same bar after being twisted; Fig. 8 is an elevation of the same; Figs. 9 to 16 inclusive are sections taken on planes indicated by the lines 9-9, 1010, etc., to Hi -16 respectively, of Fig. 8; and Fig. 17 is a development of its surface. Figs. 18, 19 and 20 are similar developments of bars having modified arrangements of ribs, Fig.

18 illustrating two sets of oppositely inclined ribs on each side of the bar, Fig. 19, two sets of intersecting oppositely inclined ribs on each side of the bar, and Fig. 20, one set of ribs on each side of the bar, each rib overlapping its adjacent rib by half its length; and Figs. 21 and 22 are sections of the bar having the development represented by Fig. 20, taken respectively on planes in dicated by the lines 2l-2l and 22-22 of Fig. 20.

Throughout these views like characters refer to like parts.

in the form of the invention illustrated in Figs. 1 to 6, inclusive, the bar A is provided with a "body f of oval cross-section and two sets of ribs and h. These ribs are oblique to the axis 0. the bar and preferably spirally arranged upon the lines of parallel helices, having an axis common with that of the bar, as 4 clearly shows. One set of ribs occupies the top of the body f and the other set the bottom. Each rib varies in crosssectional area from a maximum at its center, at the top or bottom of the bar, to a minimum at its ends, at the sides of the bar. In the present instance, the section of each rib is approximately triangular in form and as it decreases in area, the height and width of the section are gradually decreased. Obviously, the ribs might be given any other desired form of cross-section and the decrease in area mi ht be otherwise secured.

In the form 0' the invention illustrated in Figs. 7 to 17, inclusive, the bar B is pr0- vided with a body 2' corresponding in crosssection to the body f of bar A, but having more pronounced edges, 9' and k at its sides. It is provided with ribs 1 and m, similar to the ribs 9 and h of bar A. In making this bar, it is first rolled into the form of bar A, except for the slightly different section of its body, and is then twisted in a direction opposite to the direction of the ribs Z and m. Obviously, this twist of the bar may be of any desired degree, but is preferably sufiicient to balance the angularity of the ribs 1 and m and thus equalize any tendency of the bar to twist when under stress in the structure in which it is used. It is obvious that the exterior surfaces of the body portion of the bar, due to the non-circularcross-section of this portion and its twist, constitute bearingsurfaces which tend to resist the longitudinal movement of the bar through the concrete or other enveloping material. The bar A is not balanced in this way, but obviously might be rendered so by twisting it as bar B is twisted. The bar A may be used in places where the tendency to turn under stress is of little or no importance, or is not produced by the stresses of the structure, such as shear stresses.

In the form of the invention illustrated in Fig. 18, the bar C is provided withfa body 11. having a cross-section, like bar B,-'but provided with a set of ribs 0 and p on its top and a set 9 and r on its bottom, the ribs 0 and 72 being equally and oppositely inclined to the axis of the bar on the one side, and the ribs 9 and 1' being similarly inclined thereto on the other side. This bar C is not twisted and need not be, since the balancin function is provided by the equally ant oppositely inclined ribs.

In each of the bars A, B and C, the crosssections are uniform at all points, the area of the body remaining the same from point to point, and the sum of the areas of the ribs at each section being a constant. Thus, in the case of the bar A, the area cut from the body f by a plane at right angles to the axis of the bar will always be the same; and the sum of the areas cut thereby from ribs 9 and b. will always be the same, but the relative areas "cut from the ribs 9 and It will vary from point to point, as will be apparent. from an inspection of the drawing. The same relation exists in the cases of bars B and C. In the three bars, the upper ribs, designated 9, l, 0 and p, are formed in the mill by the upper roll of a pair of horizontal rolls; and the lower ribs, designated 71.. m, and '1', are formed by the lower roll of such pair. In order then, for the siun of the cross-sectional areas of the ribs (when out by a plane at right angles to the axis of the bar) to be constant, it is necessary to register the grooves in the pair of rolls by which the ribs areformed. To avoid the necessity of thus registering the rolls of the mill, I may arrange the ribs so that the sum of the areas of the ribs formed by each roll will be a constant. Thus in the form of the invention illustrated in Fig. 19, the ribs of the maintain the uniform area of the ribs atall sections. As clearly shown, the ribs t and u on the top of the bar intersect near, their opposite ends and overlap each other in the longitudinal direction of the bar far enough to bring the end of each rib in transverse line with the center of the adjacentone. The

same is true of the ribs '21 and w on the under side of the bar. In this instance, the body: has the same cross-section as bar B, although it is obvious that the form of the section may be varied without departing from my invention. In this bar, as in its predecessors, the ribs have the same individual crosssection and diminishing dimensions as the ribs of bar A, but obviously these too might equally well be varied. From what has been said, 1t will be at once apparent that no matter where a right section of the bar is taken, the sum of the cutareas of ribs 6 and u will be the same, and the sum of the cut areas of ribs '2) and w will remain unchanged. Therefore, since each set of ribs gives a constant aggregate area, it is immaterial What positidiialrelation they bear to each other and hence the rolls of the mill by which they are formed need not be registered, but may occupy" any relative position without affecting this result. In this bar, as in bar C, the balance is provided by the equally and oppositely inclined ribs of each set, ribs 25 and u on the upper side, and o and w on the lower.

Fig. 20 illustrates bar E having another arrangement of ribs which obviates the ne cessity of registering the rolls when rolling the bar. In this instance the body a: is provided with one set of top ribs 3 and one set of bottom ribs 2 and each rib overlaps its neighbor in the same set by half its length. In this way, the'suni of the cut areas of each set of ribs remains constant from point to point and consequently registration of the rolls is not required. This bar may be twisted the same as bar B in order to balance the twist of the body against the ribs. Figs. 2i and 22 illustrate the section of the body of bar E but obviously such section might be varied to suit given requirements in a variety of ways.

From the above, it will be seen that in all forms of the invention, {the ribs are small,

I of material.

regular and evenly distributed over the body of tho bar. As a result, they ma 1 he formed in the last pass of the rolling mill and without heavy reductions. This avoids the difficulty of getting two sets of rolls to work accurately with reference to the ribs, as would be necessary were heavy reductions required; it enables the bar to be formed without an excessive temperature in the roughing passes and with a continued working in the neighborhood of the critical temperature (700 to 800 (1), thus producing a .finer grain in the steel with a corres ondingly greater strength to the bar; and t e rolling of the steel at a low temperature leaves the bar practically free from scale and enables it to be rolled more accurately and uniformly as to size, with the resulting economy The oblique arrangement of the ribs en ables them to be rolled easier than transverse ribs and practically as easy as longitudinal ribs. In forming the oblique ribs, the metal has only to flow upward, downward. and forward. The ready flow of the metal is also facilitated by the uniform cross-sectional area of the bar.

It is well recognized that in rolling irregular bars in horizontal mills from round bars, and square bars rolled in V-shaped grooves, depressions and projections can he more easily and accurately formed at the top and bottom of the bar than at its sides, by reason of the more direct application of pressure by the rolls to the top and bottom of the her as it between them, I have thcrefm-e arranged the ribs in my bars with a maxi mum projs "on and cross-sectional area at their con). and gradually diminish both to a minimum at the sides of the bar. AL though a matter of minor importance, it may be noted that this form of rib thus tends to reduce the cost of production of the bar by reason of the reduced work performed by the mill in producing it. By it I also obtain practically all the advantages of a but having a continuous spiral rib Without the excessive cost and difliculties attendant upon its production.

Bars constructed according to my invcn' tion are of equal volume and practically equal exposed area per unit length, and consequently are of practically uniform temperature as they enter the last pass of the mill. This gives the finished bar uniformity of texture, strength, hardness, ductility and elasticity, and hence an equal elongation per unit length when under strain. The forms of bar, which 1 have devised, also admit of the economical production of accurate rolls which in turn give an economical bar. These rolls may be of chilled cast-iron, or steel castings, turned in the usual manner. and then grooved by means of a simple and readily obtainable revolving tool, such as a cutter commonly used in milling machines or gear cutters. Rolls which may be thus readily machined and grooved, not only may be readil" and cheaply manufactured, but also pro uce a uniform and economical product. Another feature of economy in the production of my bars consists in the ease of changing the mill from standard bars, such as rounds, squares, hexagons, octagons, ovals, etc., to in bar, and vice versa, since in either case it is only necessary to change the rolls of the last pass. Consequently, a minimum of time is consumed in shut-downs and changes. My bars may be readily produced from any of these standard shapes by working them through the proper rolls in the last pass of the mill. In addi tion to'these several economies of production possible in the rolling of bars constructed according to my invention, there are certain structural features which especially con tribute to their efiicienc-y and utility in concrete and other reinforced structures. Thus the bar, in its several forms, is free from large flat surfaces which tend to destroy the mass elfect of the reinforced structure, and which, when placed near the surface of reinforced concrete structures, are liable to cause the adjacent concrete to spall. It is also free of sharp corners and long sharp edges which tend to split the concrete. By reason of the arrangement of the ribs, alone or combined with the twist of the bar, the tendency of the bar to twist in the finished structure is avoided. Furthermore, all pockets and depressions in the finished bar are of such size and form that the pouring of the coin crete about the bar during construction will drive out the contained air and completely fill them, thus obtaining the maximum available adhesion. The shape of the bar in its several forms is also such that the centers of gravity of all right sections of the bar lie in a practically straight line coincident with the axis of the bar, and consequently the elongation of the bar will be in direct ratio to the load it carries, and local strcs due to the tendency of the bar to straighten will be avoided. The shape and arrangement of the projections and depressions oi the bar. by which bond with the concrete or other material is provided, also increases the tensile strength of the bar, since at all right sections the combined areas of the body and ribs are the same.

Although I have employed the term concycte reinforcing bar, it will be apparent that the bar may be employed in structures made up of other materials than concrete.

In practising my invention, obviously other shapes and arrangements of projections and depressions may be formed in the her without departing from the spirit and scope of my invention. I therefore do not wish to be limited to the specific forms herein disclosed, but aim to cover by the terms hf the appended claims all such alterations and moditicz lions oi the same as will ordinarily occur to persons skilled in this art.

'hat I claim as ne and desire to secure by Letters Patent of the United States is:-

1. A concrete reinforcing bar having aplane, surfaced central body .and substantially parallel isolated ribs projecting from said body and extending diagonally across one face of the bar in a general spiral direc tion, each rib varying regularly in cross-- sectional area from a maximum neat-the middle of the rib to a minimum at its ends and there merging into said body.

A concrete reinforcing bar having a plane surfaced central body of substantially oval cross-section the relatively tlat sides of the oval lying at the top and bottom of the bar, and substantially parallel isolated ribs projecting from the uppe and lower fac s of said body and extending: in each in stance diagonally arro-- one time of the bar in a general spiral directi n, ea h rib taryiug' regularly in cross se tional area 't'rnn'i a maximum near the mi ltll of th rib to a minimum at its ends and there merging: into the sides of. said body.

3. A concrete reinforcing bar ha\ in; sets of bearing faces tending to resist the tough tudinal movement of the bar through the concrete, one of said sets comprising shoulders formed by the twisting of the bar. and the other of said sets being the sides of substantially parallel isolated ribs projecting from the bar and extending diago ll across one face of the bar in a g neral spiral direction, ea h rib raeying regularly in cross-sectional area from a maximum near the middle of the rib to a minimum at,

its ends and ther m rging int he bar.

4. con rete reint ort-ing ar liming fitla' of b aring ta t-s t ntliiur to res st the Iongi tudinzl niorcnn-nt ot' the bar through the (iuiltltlt one of mid HiS (Ullljll'ltllllfl slioulders tormiul by the wisting of the bar, and

l the other of said sets being the sides of subfstantially parallel isolated ribs projecting from the bar and extending diagonally l across one face of the bar in a general spiral l directiom each rib varying regularly in cross-sectional area from a maximum near 5 the middle of the rib to a minimum at its ends and there merging into the bar, and the spirality of the ribs being equal and opposite to the twist of the bar.

5 A concrete reinforcing bar having a set of bearing faces tending to resist the longitudinal movement of the bar through the concrete, said set being the sides of substantially parallel ribs isolated from each other and extending diagonally across one face of the bar in a general spiral direction, each rib varying regularly in cross-sectional area from a maximum near the middle of the rib to a minimum at its ends and there merging into the bar U. A reinforcing bar of any cross-section haying" along its length a group of obliquely positioned projections; a second group of obliquely positioned projections staggered in l'\ lation to those of the first group; the projections of one group overlapping at; each end adjacmit projections of the other group; successive projections of the groups being relatively proportioned and arranged to provide uniform cross-sectional area of projecting material throughout the length ot' the bar; each said projection being wholly isolated and surroinnled by the normal surlace oi' the bar separating the same from i adjacent projections, and lying entirely at on side ol an axial plane of the bar Where- 4 b the url'acc ot the bar intersected by said a\ial plane remains substantially undeformed.

in o'llitt'Wi whereof; I hereunto subscribe my name this a lth day of May, 1908. WI lililA M CORYELL.

\Yauuim l. PERRY,

j Witnesses:

l Louis M. MoDoNALn. 

